Successful management of multiple pregnancies in a family with varying severity of Von Willebrand disease.

We present the obstetric history of a family of three sisters with Von Willebrand disease, managed in our centre over the course of nine successful pregnancies. The abnormalities result from inheritance of an exon 50 skipping mutation in the Von Willebrand factor gene, resulting from consanguinity. Two of the sisters were identified as having a severe phenotype with a Von Willebrand factor level of less than 5 IU/dl, with the other having a mild phenotype. Of the sisters with a severe phenotype, one had a number of prenatal complications and required early onset prophylaxis with Von Willebrand factor concentrate, whilst the other had a less complicated clinical course, only requiring Von Willebrand factor concentrate to cover labour. The sister with mild Von Willebrand disease had a rise in Von Willebrand factor levels during pregnancy and required no specialist treatment. The report highlights the markedly different clinical courses that can occur in patients with Von Willebrand disease and the different approaches to management.

Vitamin K metabolism: current knowledge and future research.

Vitamin K is an essential fat-soluble micronutrient that is required for the post-translational γ-carboxylation of specific glutamic acid residues in hepatic and extra-hepatic proteins involved in blood coagulation and preventing cartilage and vasculature calcification. In humans, sources of vitamin K are derived from plants as phylloquinone and bacteria as the menaquinones. Menadione is a synthetic product used as a pharmaceutical but also represents an intermediate in the tissue-specific conversion of vitamin K to menaquinone-4, which preferentially resides in tissues such as brain. Research into vitamin K metabolism is essential for the understanding of vitamin K biology in health and disease. Progress in this area, driven by knowledge of vitamin K and the availability of markers of vitamin K status, has already proved beneficial in many areas of medicine and further opportunities present themselves. Areas of interest discussed in this review include prophylactic administration of vitamin K1 in term and preterm neonates, interactions between vitamins K and E, the industrial conversion of vitamin K to dihydro-vitamin K in foods, tissue-specific conversion of vitamin K to menaquinone-4, the biological activity of the five and seven carbon metabolites of vitamin K and circadian variations.